MAC Code in Router

i bought a cable net connection 2weeks back from the local Cable Guy. It was working fine on my Desktop PC. But yesterday i connected my Laptop and i was not able to connect, so i called the Helpline [yes these Cable Guys have a Helpline :)]. The guy there told me that when i logged in for the 1st time from my Desktop their system registered my MAC code and would not recognize my Laptop. In order to solve this issue he suggested to get a router and code in the ID, Password, Host Name and MAC code of my Desktop.
+ Can anyone suggest me Router which takes a Ethernet cable as Input and Output. All could find in market was Routers that take Phone Line as Input and Ethernet cable Output.
+ Could a converter help to solve this issue.. Will the converter affect the speed of the cable net.
+ Can MAC code in a Router be changed to that of my Desktop so the system recognizes me even when i connect through my Laptop.

+ Can anyone suggest me Router which takes a Ethernet cable as Input and Output. All could find in market was Routers that take Phone Line as Input and Ethernet cable Output.
Most Routers are ethernet in and Ethernet out if the ones you saw had phone in ethernet out it was probably a combo Modem/Router.
You just want a standard Dlink or perferably a linksys router.
After you get this, connect your Cable Guy modem to router input
and then plug your laptop and desktop into the output ports of router. Your cable guy help line should be able to reset your mac address and register the router mac address.

i bought a cable net connection 2weeks back from the local Cable Guy. It was working fine on my Desktop PC. But yesterday i connected my Laptop and i was not able to connect, so i called the Helpline [yes these Cable Guys have a Helpline :)]. The guy there told me that when i logged in for the 1st time from my Desktop their system registered my MAC code and would not recognize my Laptop. In order to solve this issue he suggested to get a router and code in the ID, Password, Host Name and MAC code of my Desktop.
+ Can anyone suggest me Router which takes a Ethernet cable as Input and Output. All could find in market was Routers that take Phone Line as Input and Ethernet cable Output.
+ Could a converter help to solve this issue.. Will the converter affect the speed of the cable net.
+ Can MAC code in a Router be changed to that of my Desktop so the system recognizes me even when i connect through my Laptop.

I think you are confusing a router and a modem. DSL modems have a phone line input and an ethernet output. routers deal with routing ethernet connections and have multiple ethernet inputs/outputs. If you currently are only using a modem you may be using PPPoE to authenticate from the desktop and you do not have it setup for your laptop. If you get a router, this will all be solved since it can handle authentication and internet sharing between multiple computers.